The present invention relates to heat insulating shutter devices.
As disclosed, for example, in Unexamined Japanese Utility Model Publication No. 117992/1988, heat insulating shutter devices are already known which comprise a coiled shutter housing provided on an upper edge portion of a vertical wall of a building defining an opening in the wall, with a shutter outlet formed in the lower end of the housing, a shutter winding-unwinding horizontal drive roller disposed within the housing, a shutter attached to the drive roller and comprising a multiplicity of slats connected to one another so as to be wound up to a coiled form, and a guide rail provided on each of opposite side edge portions of the wall defining the opening. Such a shutter device is low in heat insulating properties since it is usually made of metal which is a good conductor of heat. However, it is required that the interior of the building be kept warm during winter and cool during summer.